<?php


$class_name = 'php0228';

//将某个变量的值，赋值给另一个变量
$php_class = $class_name;

echo '<hr>';

$var1 = 10;

$var2 = $var1;

$var1 = 20;
var_dump($var2);//10

echo '<hr>';

$var3 = 10;
$var4 = &$var3;
$var3 = 20;
var_dump($var4);//20


//echo $var2;

echo '<hr>';

$var5 = 30;

var_dump($var5);
unset($var5);
var_dump($var5);

echo '<hr>';


$var6 = 10;
$var7 = &$var6;
$var6 = 20;
var_dump($var7);
unset($var6);//删除的var6
var_dump($var7);//没有影响var7


var_dump($var8);
